Sleeve type elbow terminal



y 1951 H. A. ELLIOTT 2,553,083

SLEEVE TYPE ELBOW TERMINAL Filed May 1, 1948 INVENTOR. HOWARD A. ELLIOTT14 TTORNEV Patented May 15, 1951 SLEEVE TYPE ELBOW TERMINAL Howard A.Elliott, Detroit, Mich., assignor to Essex Wire Corporation, Detroit,Mich., a corporation of Michigan Application May 1, 1948, Serial No.24,552

4 Claims. (01. 173269) The present invention relates to an improvedsleeve type elbow terminal particularly but not exclusively adapted foruse as an electrical terminal used with automobile ignition systems andthe like.

Prior to the present invention, such sleeve type elbow terminals havebeen commonly fabricated from sheet metal stock to provide anessentially tubular L-type sleeve or socket open at both ends. Onesleeve end of the terminal is adapted for permanently receiving inelectrical contact the end of an insulated wire conductor. The othersleeve end serves as a female type sleeve terminal for detachablyengaging the mating plug or male type terminal of another conductor. Thebend at the elbow of such sleeve terminals has been a sourceof weaknessin the conventional construction. In forming the elbow the metal isunequally stressed and is weakened so that the elbow bends too readily,resulting in breakage of the terminal at the elbow.

An object of the present invention is to provide an improved angularsleeve type terminal which is particularly resistant to bending orbreakage at the elbow.

Another object is to provide an improved sleeve type elbow terminalwhich is particularly adapted for use with automotive ignition systemsand which provides an angle at the elbow of less than 90, so as topresent the terminal in use at a particularly convenient angle to theoperator.

Other objects are to provide an improved angular sleeve type terminal ofthe character described which is readily adapted for economicalmanufacture by mass production methods from strips of sheet metal stock;and to provide improved mean in such a terminal for positivelyelectrically contacting its permanently attached conductor and forsecurely gripping the insulation of the latter without the use of solderor other bonding material.

Other objects of this invention will appear in the following descriptionand appended claims, reference being had to the accompanying drawingsforming a part of this specification wherein like reference charactersdesignate corresponding part in the several views.

In the drawings:

Fig. 1 is a fragmentary elevation showing a terminal embodying thepresent invention and an end Portion of a conductor cable detachedtherefrom.

Figs. 2 and 3 are end elevations of the terminal shown in Fig. 1, takenfrom the left and right ends respectively. I

Fig. 4 is a front elevation of the terminal shown in Fig. 1.

Fig. 5 is a schematic plan view showing a strip of sheet metal fromwhich the terminal of the present invention is fabricated, andindicating not limited in its application to the details of constructionand arrangement of parts illustrated in the accompanying drawings, sincethe invention is capable of other embodiments and of being practiced orcarried out in various ways. Also it is to be understood that thephraseology or terminology employed herein is for the purpose ofdescription and not of limitation.

A preferred embodiment of the present invention comprises a sleeve typeelbow terminal which is formed by passing a strip of an electricallyconductive sheet material, such for example as a copper alloy, through aseries of progressive die cutting and forming operations.

In one of the early operations, a bowl-shaped indenture comprising aspherical or spheroidal segment is embossed into the strip in such amannor as to provide a uniformly stressed area. This indenture laterbecomes the region of the bend of the elbow and provides great strengthand resistance to bending of the formed terminal from its final angularshape. In the succeeding operations, the strip is punched and indenturedto provide gripping means and a plurality of jagged inturned tangs, thesides are rolled to the sleeve form, and the elbow shape is formed bybending the material at the spheroidal indenture.

One sleeve leg of the resulting terminal is adapted for securely andpermanently gripping the end of an insulated wire conductor insertedtherein, and is preferably clamped around the conductor in themanufacture of the terminal, although it may be clamped around theconductor on the job if desired. The jagged inturned tangs are providedby the said conductor receiving sleeve leg for embedding into andpositively gripping the insulation of the conductor. Each tang isadapted in size so that the area of the insulation cut thereby will beinsuflicient to permit stripping of the insulation from the conductor.

The conductor receiving sleeve of the terminal also provides an inwardprojecting conductor contacting nib adapted to make positive electricalcontact with an exposed portion of the conductor inserted into thesleeve. Prior to insertion of the conductor into the sleeve terminal, itis preferred that an end portion of the conductor is exposed and bentrearwardly in a U-bend against the external side of its insulation.Thereafter the conductor is inserted into the sleeve therefor with itsexposed end portion aligned to contact the aforesaid inward projectingconductor contacting nib. Upon closing the sleeve tightly around theinsulation, the said conductor contacting nib en.-

gages the exposed end portion of the conductor in positive electricalcontact.

A particular embodiment of the present invention is shown in Figs. 1through 4. The terminal:

comprises two sleeve legs I and I2 bent at a right angle around theessentially spheroidal emboss-- ment or indenture I4 at thecap or foldof the elbow. The sleeve leg I0 is adapted to receive and electricallycontact the end of an insulated,

cable I6 having the insulation I3. In order to assure positiveelectrical contact with an exposed rearwardly bent end portion 20 of thecable I6, the sleeve leg I provides the inward projecting conductorcontacting nib 22. Permanent andsecure gripping of the insulation I8 isachieved by the plurality of jagged inturned tangs 24.

The insulated conductor I6 is preferably permanently and securelyenclosed within the sleeve leg I0 during the formation of the latter,with the nib 22 contacting the exposed cable end portion 28: and withthe inturned tangs 24- cutting into the insulation I8. However, theconductor I6 may be inserted on the job if desired by opening the sleeveleg I8 along its longitudinal slit 26 (Fig. 4) which spaces the adjacentsleeve edges 28 and 30 along the line of symmetry at the interior angleof the elbow. Thereafter the sleeve leg I0 is closed tightly around theinserted conductor cable I5-I8 as described above.

The sleeve leg I2 of the completed terminal provides a plurality ofaxially extending ovallike recesses 32. Two of the opposed bars 34between the recesses 32 are crimped slightly inward, so as to provideresilient retaining and electrical contacting mean for detachablygripping a conventional male or plug-type terminal insert.

The terminal of the present invention may be economically fabricatedfrom a thin fiat strip 35 of a: copper alloy such as bronze or othersuitable electrical conducting material having the desiredstrength andforming characteristics. Fig. 5 schematically indicates one methodutilizing a progression of cutting: and forming operations through whichany particular portion of'thestrip 35 or blank formed therein issubjected in the formation of a terminal embodying the presentinvention. It is to be understood, however, that said terminal may bemade by other methods known to those skilled in the art. As here shown,the respective steps of a preferred process are lettered A through G forfuture reference, the first step being shown at A and the subsequentoperations being indicated step by step to the right in Fig. 5.

The general principles of the die cutting and forming operationsrequired. for the fabrication of a terminal of the character describedfrom a strip of sheet metal. stock are well knownto the tool and diemaking art and areaccordinglynot described herein. Briefly, the strip 35is intermittently indexed. from left' to rightthrough a series ofprogressive cutting and forming dies. Each progressive die performs itsworkopera.- tion on the portion of the strip indexed; thereat; so;,that:the resulting strip will appear somewhat as indicated-in Fig. 5. A.preferred sequencev of. operation. in, the formation of the terminal?rolled inward in the later operations.

shown is described in more detail in my co-pending application, SerialNo. 24,551, filed May 1, 1948, to which reference is hereby made for thedisclosure of any additional details which may be required.

As a first step, the end of the strip 35 is embossed with the saidspheroidal indenture I4 which later becomes the. fold or cap of theelbow. Itwill be apparent'to those skilled in the art that the indentureI4 may be formed at any one of various stages in the progressiveformation of the terminal, provided that the portion of the strip 35whereat the indenture I4 is formed is still essentially fiat.Theindenture or embossment I4 wilt be: of less value as a reinforcementif formed after the sidewalls of the terminal are Furthermore, the earlyformation of the indenture I4 permits its use for centering the strip 35as it is progressively indexed to the subsequent cutting andformingoperations.

I-he embossing of the indenture I i stresses and work hardens thematerial of the strip 35 at the region which eventually becomesthe foldof the elbow and also provides an essentially spheroidal surface for theelbow capwhich uniformly distributes forces tending to distort the elbowfrom its final angular shape. Thus isprovided an exceptionally strongangle type terminal which is particularly resistant: to bending at theelbow. The strengthening aiiordedby'the spheroidal indenture IA may alsobe achieved by raising the latter in the strip 35, Fig. 5, so thattheresultant elbow capwill be concave rather than convex. However, thepreferred: construction shown permits afolding and blending of. theterminal about the convex indenture lid and provides a terminalofimproved appearance. Likewise, the present invention is obviouslynotlimited to the spherical embossment. M. at the elbow,. since embossedindentures having other surfaces, as for example asymmetric multi-facetindenture, will provide a Work-hardened, stressrdistributing elbowreinforcement within the. spirit of thepresent invention.

In the step-B,.the strip 35 is blanked out-around the indenture, I4,leaving the resulting blank connected: to=the bodyof'the strip by theconnecting neck 35.v Simultaneously the truncated triangular: notches 38are cut. in the.- blank to remove the excess; material at the. lateralsides of the indenture: I4 and to. permit formation of. the elbow bend.Each. notch 38 is identified by the small axially extending base 40.terminating in the axially spaced points 42 and 4t referred: to;hereinafter.

In. subsequent operations; indicated at C, the plurality ofOVEilr'likfi'. recesses 32. are formed. 'As" indicated: at D,.the. bars3A1 between thetwolateral pairs: of recesses. 32. are crimped upwardly,but the aforementioned nib; 2-2 and jagged tangs 24' are raised fromthe. underside of the portion of the. blank which eventually'become thesleeve leg I 0- Intheoperations indicated at E, the afore-- mentionedlaterali edges 28.: and. 311- of. the leg II] are bent slightly upward.and? the corresponding: lateral edges 45 and 48 of the leg' H? aresimilarly bent; upward. At'a later stageathe edges 28', 3.0,

'46, anda IB; are: rolled. further, upwardand towardeach; other-to formthe ,semirclosed sleeves ber indicated at F. In the finaloperations,.the.

legs Illand: 'l2i areibent. at right anglesto. each othen' as;indicafted: at: G; and. the. sleeves: thereof fare closed to the finalposition indicated iinliigszl-l f through 4. If desired, prior to thefinal closing of the sleeve leg H), the cablelfi-IB is inserted andpermanently secured therein by folding the sleeve leg [9 tightly aroundthe insulation i8 as heretofore described.

In the elbow bending operation, the axially spaced points 42 and 44 atopposite ends of each base 40 are compressed and swagged essentially toa single thickened. reinforcement 50, Fig. 1, at the base of the slit 52which remains after the elbow forming operation as a remnant of therecess 38. Not only is the base of the slit 52 reinforced by thethickening of the excess material thereof resulting from the compressionof the base 40 to essentially a single point, but the swagging andflattening operations work harden the thickened material 59 resulting inthe formation of an exceptionally strong reinforcement for the bend. ofthe elbow.

Although the present invention is illustrated by means of a right angleelbow, it is apparent that an elbow may be provided. at other than aright angle. An essentially 45 angle is particularly desirable in someinstances, as for example with certain types of automobile ignitionsystems, and permits the terminal to be conveniently faced toward theoperator in use.

From the foregoing, it is apparent that I have disclosed a superiorsleeve type elbow terminal which is readily adapted for efficient andeconomical manufacture by conventional progressive automatic die cuttingand forming processes. The completed terminal provides means forsecurely and permanently gripping a cable in electrical contacttherewith and is characterized by both an improved appearance and ingreatly increased strength and resistance to bending at the elbow incomparison to similar terminals of conventional construction.

Having thus described my invention, I claim:

1. A sleeve type elbow terminal formed of a strip of sheet material andincluding a pair of joined legs, one leg being secured to a conductor, awork-hardened embossed spherical segment comprising the cap of the elbowwhich connects the adjacent ends of said legs to reinforce the apex ofthe elbow and form a smooth rounded 6 contour thereat, said sphericalsegment comprising at least half the width of the strip at the pointwhere it is formed, the elbow terminal including a slit in the bottomthereof which essenially bisects the angle of the elbow and extendstoward and terminates short of said elbow cap.

2. An elbow terminal according to claim 1 and further characterized inthat the center of curvature of the spherical segment lies upon theintersection of the longitudinal axes of said legs.

3. An elbow terminal according to claim 1 and further characterized inthat the center of curvature of the spherical segment lies upon a linewhich bisects the angle of the elbow.

4. A sleeve type elbow terminal formed of a strip of sheet material andincluding a pair of joined legs, one leg being secured to a conductor, awork-hardened embossed spherical segment comprising the cap of the elbowwhich connects the adjacent ends of said legs to reinforce the apex ofthe elbow and form a smooth rounded contour thereat, said sphericalsegment comprising at least half the width of the strip at the pointwhere it is formed, the elbow terminal including a slit in the bottomthereof which essentially bisects the angle of the elbow and extendstoward and terminates short of said elbow cap, and a flat thickenedreinforcing portion at the base of said slit on each side of theterminal which joins the side walls of the legs of the terminal.

HOWARD A. ELLIOTT.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 376,666 Lee Jan. 17, 1888 994,930Johnston June 13, 1911 1,553,060 Anderson Sept. 8, 1925 1,566,768 OtisDec. 22, 1925 1,808,335 Aufiero June 2, 1931 1,930,639 Berthold Oct. 17,1933 2,175,759 Olson Oct. 10, 1939 2,430,543 Tinnerman Nov. 11, 19472,433,358 Garberding Dec. 30, 1947

